The Boogeyman is a mythical creature used by adults to frighten children into good behavior.
Jim Henson's Muppets Annual 1982 features the Bogeyman (spelling in accordance with the British publication) depicted as a large, knock-kneed, purple creature with blue fur (illustrated by Bruce McNally). In the story, he's a member of POPCORNS (a club for "People Other People Consider to be Other than Real Normal Specimens") along the likes of Kermit the Frog, Santa Claus, The Sandman, Maxine the Tooth Fairy, and others. Kermit says he looks weird, but he sometimes plays chess with him after meetings. He joins the Muppets on Christmas morning where he has befriended Sweetums.